Cylinder lock



June 14, 1955 E. A. s'rEPHENsoN CYLINDER LOCK Filed Feb. 26, 1953 United States Patent i O CYLINDER LOCK Edward A. Stephenson, New York, N. Y.

Application February 26, 1953, Serial No. 339,010

5 Claims. (Cl. 70-364) This invention relates to locks, and more'particularly to locks of the type that are commonly designated as cylinder or pin-tumbler locks.

A conventional cylindrical lock comprises an outer cylinder or housing having a plurality of parallel springpressed driver pins, and an inner cylinder or barrel that is positioned within the outer cylinder and that is provided with a plurality of tumblers, each of which is adapted to align with a corresponding driver pin in the outer cylinder. The inner cylinder has a keyway for reception of a key that is notched or scored along one edge for registration with the ends of the tumblers. The notches on the key are so coordinated with the lengths of the tumblers that the latter are moved by the key so,

that their outer ends are coincident with the periphery of the inner cylinder. With the parts in this relative position the inner cylinder may be rotated with respect to the outer cylinder to open unlocked position.

Experience has demonstrated that locks of the type described may be readily actuated to open position Without the use of a key. This is accomplished by what is known as picking the lock, which procedure merely consists of applying a turning force, as if to open the lock, and simultaneously inserting a pick inside the keyway to successively actuate each tumbler to unlocking position. The'action of the pick is usually suicient to raise a selected tumbler, and the turning force on the lock is generally adequate to turn the inner cylinder a necessary increment to maintain a picked tumbler in proper position while the next tumbler is being picked.

A number of attempts have been made in recent years to overcome the objections in cylinder locks. None of these attempts have been successful, however, due to inherent weaknesses in construction and design.

A primary object of the invention is to provide a cylinder type lock having its parts so constructed and arranged 5 as to minimize the possibility of its being opened by instrumentalities other than a key that is normally used for this purpose.

Another object of the invention is to provide a cylinder type lock having incorporated therein improved devices for preventing operation of the lock without the use of a proper key.

A further object of the invention is to provide a lock of the character indicated that is simple in design, reasonable in initial and maintenance costs, and capable of performing its intended functions in an entirely satisfactory and trouble-free manner.

To the end that the foregoing objects may be readily attained, a lock constructed in accordance with this invention preferably comprises a housing or outer cylinder having formed therein a plurality of openings, including a longitudinal through bore, a plurality of parallel driver bores, and at least one slot that is intermediate and communicates with the longitudinal bore and a pair of successive driver bores. An inner cylinder or barrel is positioned within the longitudinal bore of the outer cylinder and is rotatable with respect to the outer cylinder when j 2,710,536 Patented June 14, 1955 ICC the parts are in a predetermined relative position. The inner cylinder has a longitudinal keyway, a plurality of tumbler bores communicating with the keyway and at least one slot extending inwardly from the periphery of the inner cylinder and communicating with a pair of successive tumbler bores.

When the lock parts are in locked position, the slot in the inner cylinder is in alignment with the slot in the outer cylinder, and each tumbler bore is in alignment wtih a corresponding driver bore. Also, a pair of rela- .tively slidable bars is positioned one above the other, one of the bars being at least partly disposed in and slidable along a corresponding slot. A spring-pressed driver pin is slidable in each driver bore, while a tumbler is slidable in each tumbler bore.

The parts are so constructed and arranged that the inner cylinder may be turned only when the bars are moved to proper position, as will be explained in greater detail further along. For best results it is recommended that a plurality of pairs of bars, preferably three pairs, be employed with corresponding driver pins and tumblers as is illustrated in the accompanying drawing.

The enumerated objects as Well as other objects together with the advantages of the invention will be readily understood by persons skilled in the art upon reference to the following detailed description, taken in conjunction with the accompanying drawing that respectively describe and illustrate a lock constructed in accordance with the invention.

In the drawing:

Fig. 1 is a central longitudinal cross sectional view through a lock embodying the invention and illustrates the relative position of the elements within the lock prior to subjecting the same to the action of a proper key;

Fig. 2 corresponds to Fig. l and illustrates the relative position of the elements within the lock with the proper key in position preparatory to opening the lock;

Fig'. 3 is a view taken along line 3-3 of Fig. 2; and Fig. 4A is an enlarged isometric view of one of the bars shown in the other views.

` 4Referring now to the drawing wherein like reference:

' V;` provided with a plurality of parallel driver bores 13 that are normal to the axis of bore 11. Pairs of bores 13- cornmunicate with corresponding slots 14 that extend .upwardly from the surface of the housing that defines bore 11.

An inner cylinder or barrel 15 is positioned within bore 11 and is provided at one end with an integral ange 16 that registers with recess 12. The barrel has a plurality of parallel tumbler bores 17, each of which is adapted to align with a corresponding driver bore. As in the case of the housing, pairs of bores 17 communicate with lcorresponding slots 18 formed in the barrel. Slots 18 are adapted to align with slots 14 in the housing. A longitudinal keyway 20 merges with tumbler bores 17.

The diameter of each tumbler bore 17 is substantially greater than the width of keyway 20, whereby to provide shoulders 2l for limiting downward movement of tumblers that will be described further along herein.

Freely slidable in each driver bore 13 is a driver pin 22 that is normally and yieldingly urged in a downward direction by a compression spring 23 which is positioned within a corresponding driver bore and located directly above the pin. The driver pins differ from each other only in length. A tumbler 24 is freely slidable in each tumbler bore 17. As in the case of driver pins 22, tumblers 24 diier from each other only in length. Intermediate the lower ends of successive pairs of driver pins 22 and the upper ends of corresponding tumblers 24, is a pair of bars consisting of an upper bar 2S and a lower bar 26.

As is best shown in Figs, 3 and 4, each bar has a planar front surface 27 that is parallel to a planar rear surface 28, and a planar top surface 30 that is generally parallel to a bottom surface 31. Surfaces 30 and 31 merge in` arcuate end surfaces 32. Lower bars 26 are preferably identical with upper bars 25. Each upper bar 25 is positioned, at least in part and slidable, in a corresponding slot 14, while each lower bar 26 is positioned and slidable in a corresponding slot 18.

By virtue of the construction illustrated and described, the bars are tilted with respect to the horizontal when the lock is in a locked position (Fig. l) and each upper bar extends above and below the peripheral surface of the barrel thereby preventing rotation of the barrel with respect to the housing. Upon introduction of a proper key 33 in keyway 20, tumblers 24, bars 26 and 25 and driver pins 22 are all moved upwardly to the relative position shown in Fig. 2, whereby the abutting surfaces of the upper bars and the lower bars are substantially coincident with the peripheral surface of the barrel. This permits rotation of the barrel relative to thehousing and operation of the lock to unlocked position.

It will be apparent from the foregoing that it is considerably more dicult to pick locks embodying my invention than conventional cylinder locks. By virtue of my arrangement of pairs of bars 25, 26 and corresponding pairs of tumblers 24 and driver pins 22, both tumblers of each pair must be simultaneously picked and moved to unlocking position.

It is to be understood that the form of my invention, herewith shown and described, is to be taken as a preferred example of the same, and that various changes in shape, size and arrangement of parts may be resorted to without departing from the spirit of my invention, or the scope of the subjoined claims.

I claim:

l. Ina lock of the character described, a housing having formed therein a longitudinal bore, a plurality of parallel driver bores, and at least one slot that is intermediate and communicates with the longitudinal bore and a pair of successive driver bores, a barrel in the longitudinal bore and rotatable with respect to the housing, said barrel having formed therein a longitudinal keyway, a plurality of parallel tumbler bores communicating with the keyway, and at least one slot that extends inwardly from the periphery of the barrel and communicates with a pair of successive tumbler bores, the slot in the barrel being adapted to align with the slot in the housing, a

spring biased driver pin slidable in each driver bore, a tumbler slidable in each tumbler bore, a pair of bars, each of the bars being at least partly disposed in and slidable along a corresponding slot, said bars being slidable in response to sliding movement of the tumblers and drivers in the corresponding bores.

2. A lock in accordance with claim 1 wherein the bars are rectangular in transverse cross section, a surface of one of the bars abutting a corresponding surface of the other bar, an end of each of a pair of driver pins bearing against the surface of one of the bars that is remote from the other bar, an end of each of a pair of tumblers bearing against the surface of the other bar that is remote from said one of the bars.

3. A lock in accordance with claim 2, wherein the end surfaces of the bars are arcuate.

4. In a lock of the character described, a housing having formed therein a longitudinal bore, a plurality of parallel vertical driver bores, and at least one slot that is intermediate and communicates with the longitudinal bore and a pair of successive driver bores, a barrel in the longitudinal bore and rotatable with respect to the housing, said barrel having formed therein a longitudinal keyway, a plurality of parallel tumbler bores communicating with the keyway, and at least one slot that extends inwardly from the periphery of the barrel and communicates with a pair of successive tumbler bores, the slot in the barrel and the tumbler bores aligning, respectively, with the slot in the housing and the driver bores, a pair of relatively slidable bars arranged one above the other, each of the bars being at least partly disposed in and slidable along a corresponding slot, a driver pin in each driver bore, resilient means normally and yieldingly urging each of a pair of driver pins against the upper bar, and a tumbler in each tumbler bore, an end of each of a pair of tumblers bearing against the surface of the lower bar remote from the upper bar.

5 A lock in accordance with claim 4 wherein the bars are rectangular in transverse cross section, the lower surface of the upper bar abutting the upper surface of the lower bar, the end surfaces of the bars being arcuate.

References Cited inthe file of this patent UNITED STATES PATENTS 1,911,324 Pacher May 30, 1933 2,021,185 Hurd Nov. 19, 1935 2,408,283 Wollin Sept. 24, 1946 2,426,104 Johnstone Aug. 19, 1947 2,660,876 Spain Dec. 1, 1953 FOREIGN PATENTS 153,145 Austria Apr. 11, 1938 

